1915] Ecological Foundations of Applied Entomology 11 
to pick and choose at random, being quite without the guidance 
of any general knowledge of the physiological sensibilities of 
the species. 
We know that certain insecticide substances in solution or 
emulsion are effective against it in a way to make them prac- 
tically available, but we do not know how or by what proper- 
ties they produce their fatal effects and we are consequently 
without definite guidance in our search for other such insec- 
ticides. 
We know that any and all measures against this insect are 
of comparatively little avail if undertaken sporadically, by 
an individual only here and there; that for their fair and full 
effect they must be made the fixed policy and practice of whole 
communities, actuated by the community motive as well as 
the personal one. We know indeed that a large part of our 
applied entomology fails of its application because communities 
are not brought to the point of codperative action in the gen- 
eral interest; but we do not know—we have scarcely discussed 
among ourselves—the best means of appeal and the best methods 
of organization and management to effect these results, without 
which much of our economic entomology must fall practically 
short of the economic end. 
We realize that the actual utility of all our work depends 
upon a general knowledge of its practical product, and of pos- 
sible methods of its utilization in every case arising, and on an 
exercise of a sound judgment in the adaptation of such methods 
to the conditions of the time and place; but we are far from any 
kind of satisfying success in making such knowledge the com- 
mon property of the people most concerned and in training 
and assisting the common judgment to make the best use of the 
knowledge they possess. 
We well know that no people can be brought to do spon- 
taneously all that they ought to do in our field in the common 
interest, and that education, persuasion, encouragement, in- 
citement, and organization even, must be supplemented by 
legal requirement and by law enforcement if the people are not 
to suffer clearly avoidable losses of property, comfort, health, 
and life itself, due directly to insect infestation, and we have 
made considerable progress of recent years in securing legis- 
lation, state and national, in some parts of this field; but it still 
